In its simplest form, prior art continuous wave CW radar emits a single frequency continuous wave. By measuring the Doppler shift of the return signal, the CW radar can determine the velocity of detected objects. By linear frequency modulation (sawtooth) of the continuous wave in a CW radar, a frequency-modulated continuous wave FMCW radar system is provided. The frequency modulation of the CW has the advantage that also the distance to a detected object can be determined. Such a FMCW radar system is known from U.S. Pat. No. 3,789,398. The FMCW radar is mainly motivated by the fact that it minimizes the peak-to-average power ratio for the radar transmit signal. Its applications are thus as whispering radar, used to defeat detection of the radar signal.
The FMCW radar is however limited to said radar function and lacks any multifunctional capability.
Moreover, the FMCW radar exhibits poor signal cohabitation between its radar function and environmental signals.
There is thus a need for an improved transmitter/receiver arrangement removing the above mentioned disadvantages.